Add lispflowmapping performance tests

Add lispflowmapping performance tests

Add test to detect regressions in mapping resolution performance of the
Mapping Service when used through the LISP Southbound Plugin.

First, add a script (loosely based on Jan Medved's
flow_config_blaster.py) to create 10.000 simple IPv4-to-IPv4 mappings to
ODL through RPCs.

Second and a script to generate a .pcap file containing 10.000
Map-Requests for each of those mappings in a randomized order. The .pcap
file can then be replayed at arbitrary speeds.

Third, use `udpreplay` to send the prerecorded lookup requests in the
.pcap file at a rate of 100.000 packets/second for 1000 times for a
total of 100 seconds.

Finally, compute the reply rate by reading the Tx packet counter from
the southbound statisitics using RPC and dividing it by the number of
seconds the packet generater was active.

Change-Id: Ib4de1782aa32b7e010f22e12fbd04b2f53579fb1
Signed-off-by: Lorand Jakab <lojakab@cisco.com>